How to use Modbus with TSX3721 Micro

[Lare]

I think that limitation comes from PL7 ter port / firmware, because max number of integers should be 125.
http://modbus.control.com/thread/1249550734

Also from twido PLC I can read 125 integers at one time, with same cable, which I used with PL7 (TSX PSX1031).

I only downloaded your program to PLC, and then I put PLC to Run mode. I didn't do anything to your PLC test program, it works as it is now.

I noticed that you data format is selected to binary, change it. Even that if communication works you should see values on binary format now. (there should be 1 still on at modbuss address 40001 or 400001.

 

[joigunni]

I embarrassed a bit, maybe a bit more than that. I never put the PLC-system in run mode, which was the main thing. Now everything works, and I've learned a lot. The PLC and Citedt are now working together and the lights in my Citect-windows are now illuminated.

Two more questions. (Almost not dare to ask) how do I set my PLC in the Run Mode, so it will always be in the Run, even after restart.
And one more:
% MW0 (PLC) = 40001 (Tester) = 40000 (Citect ).... and ......% M0 (PLC) = 10001 (Tester) = 10000 (Citect). It works like that in my Citect, is that normal?

Thanks for all your help and thanks for all the time you spent helping me.

 

[Lare]

So it was eventually only little problem at PLC


On PLC Rack view, double click PLC card. (Hardware configuration) Then you have to select automatic start to run.
Also you maybe want unselect %MW reset at cold restart.
But if I remember right, you still have to put program manually to run mode after you have downloaded program to PLC.

At same configuration window you can change scan time settings for PLC.

From sowtware configuration you can change how many timers, drums and integers are available on PLC program.


On PL7 modbus address mapping goes this way:

000001 = %M0 (read/write)
000002 = %M1 (read/write)
...
000256 = %M255 (read write)


100001 = %M0 (read only)
100002 = %M1 (read only)


300001 = %MW0 (read only)
300002 = %MW1 (read only)

400001 = %MW0 (read/write)
400002 = %MW1 (read/write)

But this is not same on all manufactures/PLC's.

On some PLC's if you read modbus addresses 1x you can read binary inputs directly. And if you use modbus address 3x you can read analog inputs directly.
On PL7 1x and 3x addresses are also mapped to memory bits and words, not to inputs. So if you want read analog inputs or binary inputs, you have to copy them to memory addresses first on PLC program.


I think that, why citec address 40000 is same as 40001 on modbus tester, is because Citec uses so called zero based addressing for modbus and modbus tester uses one based address format.

On some OPC servers you can also select if you want use zero base or one based address format.

If you use zero based, then %MW0 = 40000
but if you use one based, then %MW0 = 40001

Someone maybe can correct, if something is writed wrongly...